CN104565187A - Helmholtz damper for gas turbine with cooling air flow - Google Patents

Abstract

The invention relates to a Helmholtz damper with cooling air flow for a gas turbine. A Helmholtz damper (10) for a combustor of a gas turbine comprises a casing (1) defining a damping space (11), from which a neck portion (2) extends, and The damping space has a flow path (F) for cooling and purge air with an inlet hole (6) and an outlet hole (3) leading to said enclosure (1), wherein said outlet hole (3 ) is formed in said neck part (2), wherein a seal (4) is arranged at said neck part (2) near said outlet hole (3) for cooling and purge air, so that for all The aforementioned seal (4) provides cooling.

Description

Helmholtz damper with cooling air flow for gas turbines

technical field

The invention relates to the field of gas turbine technology and in particular to vibration dampers and seals for combustors or burners of gas turbines. It relates to a device for thermoacoustic damping and a flexible annular seal between concentrically fitted gas turbine combustor components.

Background technique

Known gas turbines comprise one or more combustion chambers or burners including several burners, into which fuel is injected, mixed into the air flow and combusted in order to generate high-pressure flue gases which are expanded in the turbine. During operation of the gas turbine, oscillations may occur and thermoacoustic vibrations occur. This not only causes acoustic disturbances, but may also cause mechanical damage to components of the gas turbine. In order to reduce the thermoacoustic vibrations during operation of the gas turbine, it is known to install so-called damping devices, in particular Helmholtz dampers, in the combustion system. Such a Helmholtz damper includes a casing defining a damping space from which a neck portion extends and providing a flow path for cooling air in the damping space so that the temperature during operation, Especially the temperature at the neck portion of the Helmholtz damper remains within predetermined limits. Therefore, such a damping device for a combustor or a burner of a gas turbine needs to be supplied with sufficient cooling air, which is guided to the neck portion of the damper.

On the other hand, such gas turbines must be provided with sealing arrangements between separate turbine components, especially at the interface between the injector and the combustor, or at other interfaces such as the combustion chamber liner and the transition piece place. For the purpose of sealing between components of gas turbines it is known to use circumferential metal seals. In gas turbines, such flexible annular seals are used to provide adequate sealing between concentrically mounted gas turbine combustor components. In order to ensure a long life and efficient sealing between the components of the gas turbine, the seals of the combustor components are conventionally equipped with means for cooling the seals during operation of the gas turbine. Also in order to avoid oxidation of the components it is necessary to direct the air flow of cooling and purge air to especially the top portion of such seals of the burner components. Therefore known seals, such as hula seals, are not only complex in their design, but also require an additional supply of cooling and purge air in the gas turbine, which increases the necessary Airflow requirements for cooling air.

These different air flows for the purpose of cooling the dampers and seals may cause an increase in _NOx emissions and may lead to problems with regard to the operational stability of the injector and burner. In addition to possible negative effects on NO _x and CO emissions, insufficient cooling of so-called Helmholtz dampers also reduces the damping efficiency during operation of the gas turbine. In known arrangements for damping and sealing it is therefore necessary to provide a corresponding supply of cooling air at the interface of the burner components for both purposes, thermoacoustic damping and cooling of the sealing arrangement. The design of the damping and sealing means is therefore rather complex and may lead to an increase in the overall cost of such a gas turbine and has a negative impact on operating efficiency and is disadvantageous with regard to environmental constraints.

Taking these disadvantages into account, it is an object of the present invention to provide a Helmholtz damper for a combustor or burner of a gas turbine in low-emission operation, whose components in the combustor are thermoacoustically damped and High efficiency in sealing. Furthermore, with the vibration damper according to the invention, the influence of the vibration damping and sealing system on the running stability is to be reduced.

Contents of the invention

According to the invention, this problem is solved by a Helmholtz damper with the features of claim 1 . Further developments and preferred embodiments of the invention are the subject of the dependent claims.

A Helmholtz damper for a combustor or a combustor component of a gas turbine according to the invention comprises a casing defining a damping space from which a neck portion extends and the damping space has a and/or a flow path for purge air, the flow path having an inlet hole and an outlet hole leading to the enclosure, wherein the outlet hole is formed in a neck portion of the enclosure, and the shock absorber is characterized in that the seal A member is arranged at the neck portion near the outlet hole for cooling and purge air so as to provide a cooling effect on the seal. That means that the Helmholtz damper according to the invention is not only particularly suitable for the purpose of thermoacoustic damping, but at the same time provides an efficient seal for adjacent components of the burner interface. The seal is arranged in the region of the outlet opening of the cooling air flow path, so that the seal is cooled directly by the cooling and purge air from inside the Helmholtz damper. In this way, a separate supply of cooling air to the shock absorber and seal is avoided. This leads to a reduction in design complexity, since a separate supply of cooling or purge air for sealing on the one hand and thermoacoustic damping on the other hand is no longer necessary.

Furthermore, the total amount of air flow is greatly reduced, for example up to half of the cooling air flow required for gas turbine operation in conventional installations. The operation of the burner is also more stable due to the reduced mass flow of air and thus reduces _NOx and CO emissions. However, the Helmholtz damper of the present invention is highly effective in limiting or eliminating vibration amplitudes during operation of a combustor of a gas turbine, while providing the required sealing action. The operating range of a gas turbine equipped with such a Helmholtz damper is very large due to the efficient cooling of the two elements, namely the damper envelope and the seal. Owing to the constant air temperature especially at the neck portion of the shock absorber envelope and the seals arranged in the air flow of the cooling air, stable operation and a long service life are imparted to the components.

According to an advantageous aspect of the invention, the Helmholtz damper is characterized in that there is a common supply of cooling and purge air for the damper and the seal. The damper and the seal provided in the neck portion of the Helmholtz damper thus share a single supply for cooling air. The means for supplying cooling and purge air are connected, for example, to the inlet openings of the enclosure of the Helmholtz damper. The cooling air flow from the inlet hole passes through the interior of the enclosure and the neck portion of the damper, providing the required cooling of the damper for damping thermoacoustic vibrations, and then flows directly into the region of the outlet hole The seals are thus cooled by the same cooling and purge air flow. By sharing the common supply of cooling and purge air in the Helmholtz damper, separate devices for generating and supplying cooling air are no longer required for these two components, seal and damping element. This results in an overall considerable reduction in air consumption and thus cost and a more stable operation of the gas turbine, since compared to a combustion system with separate means for supplying cooling air to the seals and damping means, the Cooling air added in the combustion chamber.

According to an advantageous aspect of the Helmholtz shock absorber of the invention, the seal is an integral part of said neck portion of the shock absorber envelope. In this way, the seal is part of the Helmholtz damper itself, or it is firmly attached to the neck part of the enclosure. This facilitates the installation of the vibration damping and sealing system in the combustion system of the gas turbine. For example, there is no need to provide separate connection means for the seal and the vibration damping means, as is the case in the prior art. Furthermore, in the case of the seal as an integral part at the neck part of the Helmholtz damper, the cooling of the seal is enhanced: the neck part which has been cooled by the cooling air flow transmits the cooler temperature directly to the The sealing part, the sealing part is an integral part of the neck part of the shock absorber.

According to yet another advantageous aspect of the Helmholtz shock absorber of the invention, the neck portion of the envelope of the shock absorber has an extended length for accommodating said seal and/or fastening means, the fastening means Used to fasten the shock absorber in the combustion system of the gas turbine. From the point of view of conventional Helmholtz shock absorbers of the prior art, the length of the neck portion is extended, where a rather short neck part. Thanks to the extended neck section, the fastening of the Helmholtz damper to the interface of the combustion chamber is facilitated. Furthermore, by virtue of its extended length, the neck part is particularly suitable for arranging the seal in the region in which the cooling air flow exits the envelope of the Helmholtz damper. For example, the connection means for mounting the shock absorber to the interface in the transition wall or the combustion chamber is provided on one side of the neck portion, while the seal is mounted or provided on the opposite side of the neck portion. The complete Helmholtz damper is therefore fixedly attached to the port or wall of the burner, thus ensuring vibration damping. The seal on the other side of the neck portion may experience sufficiently large displacements within an elastic range without losing its sealing efficiency. Through these measures, a combined efficient thermoacoustic damping and sealing is achieved by means of the same Helmholtz damper arrangement.

According to a further advantageous aspect of the Helmholtz damper according to the invention, the outlet opening for the cooling and purge air flow is provided with a flow guide towards said seal at the neck portion of the enclosure orientation. The concentrated cooling air flow is thus directed to the seal, which is arranged in the neck portion in the region of the outlet opening of the Helmholtz damper. An increased cooling effect on the seal is thus achieved. The seal and the neck portion of the Helmholtz damper are thus protected from hot combustion gases flowing in the adjacent combustion region of the combustor or burner of the gas turbine. By means of such flow guiding elements, which can be provided, for example, in the form of air flow vanes, a specific flow pattern can be produced in the region of the seal and the neck part of the Helmholtz damper so that during operation of the gas turbine The cooling effect can be adapted to the corresponding design of the combustion chamber or gas turbine and the flow path of the hot gases.

According to yet another advantageous aspect of the Helmholtz damper of the invention, the neck portion of the enclosure is provided with fastening means to the interface of the combustion chamber. The interface may be, for example, a liner-front panel interface or a liner-support interface in premix burners or so-called SEV burners. Furthermore, the fastening means at the neck portion may be suitable for mounting the combined damper and sealing arrangement according to the invention to the front panel of the burner, between the bushings or other components of the gas turbine. Examples of fastening means, in the sense of a mounting flange, are straight wall sections for screwing or welding. Other types of fastening means may also be provided.

According to a further advantageous aspect of the Helmholtz damper according to the invention, the seal is arranged on the circumferential outside with respect to the damper envelope. That means that the damper is located radially more inwardly than the seal, which is located radially outwardly with respect to the envelope forming the damping body. According to an alternative embodiment of the invention, the seal is arranged circumferentially inside with respect to the envelope of the Helmholtz damper. Depending on the respective localized hot gas flow pattern in the combustion system of the gas turbine, it may be advantageous to place the seal radially inward or outward of the damper. By changing the position of the seal relative to the Helmholtz damper enclosure, the sealing and damping efficiency of the device can be further improved. For example, the outlet aperture and the neck portion of the enclosure can be realized at a lateral position of the enclosure, and the seal on the neck portion is provided either radially inside or radially outside this laterally offset neck portion. By means of such a damper/seal combination, the Helmholtz damper according to the invention can be adapted to the corresponding flow pattern of the hot combustion gases and/or to the corresponding free flow in the combustor system of the gas turbine. space. As a result of these measures, the vibration damper according to the invention is also particularly suitable as a mounting part for a retrofit part, or it is well suited for later integration in a burner or burner as a telescoping design.

According to a further advantageous aspect of the Helmholtz damper according to the invention, the seal is segmented along the sealing surface. With the segmented seal, heat transfer from one part of the seal to the other is reduced. Furthermore, the segmented form allows for some displacement of the segments of the seal in the lateral direction due to contraction or deformation of the gas turbine components. In an alternative realization, the seal is realized as a single piece, which is made, for example, of a suitable spring steel material or a similar material.

According to yet another advantageous aspect of the Helmholtz damper according to the invention, the seal is a spring-type seal, and in particular a hula seal or an E-seal. With the spring-type seal, large displacements can be accommodated in the elastic range of the turbine component without losing the sealing efficiency required for the sealing part of the Helmholtz damper. E-seals provide a seal designed for low or moderate force conditions and high spring recoil to achieve the large displacement required in certain applications in gas turbine combustion systems . A so-called hula seal is generally defined as a system of leaf springs formed as a circular ring for sealing between two concentric elements, such as at the interface between a burner or burner of a gas turbine. Slip interface joints or annular gaps. Both types of seals have been shown to be particularly suitable in combination with Helmholtz dampers, since Helmholtz dampers are the subject of the present invention.

According to yet another advantageous aspect of the Helmholtz shock absorber of the invention, the envelope of the shock absorber is a single-space device. For enclosures as single-space devices, Helmholtz dampers are particularly suitable for low-frequency pulsations and vibrations. Depending on the expected or actual form of frequency oscillations and pressure oscillations in the combustion system of the gas turbine, Helmholtz dampers can be used accordingly.

According to an alternative embodiment of the invention, the Helmholtz damper is provided with a casing, which is a segmented space device. Segmented space units are well suited to provide efficient vibration damping in the presence of high frequency pulsations. In both cases, the segmented space device and the single space device, in particular the neck portion of the enclosure, is cooled by a flow of cooling air coming from the inlet hole and passing through the neck portion towards the outlet hole. The temperature range of the envelope of the Helmholtz damper is kept within a predetermined temperature range so that there is no considerable change in the damping function during operation of the gas turbine. A more predictable and efficient thermoacoustic damping is thus achieved.

According to yet another advantageous aspect of the invention, the enclosure of the Helmholtz damper is designed for changing the space of the damper. The Helmholtz damper of the present invention is provided with an adjustable space for the purpose of damping vibrations in different frequency ranges or vibration ranges. A more flexible use over a wider range of applications is thus conferred. The volume of the enclosure can be varied, for example, by varying the segmental dimensions of the enclosure, the neck length of the neck portion of the enclosure and/or the size of the outlet aperture located in the neck portion. For a person skilled in the art, there is the possibility of further adjusting the damping space of such a Helmholtz damper envelope. By virtue of this variation and modification of the damping space, the efficiency of the damping can be further increased, while the damper according to the invention provides an excellent sealing effect.

According to a further advantageous aspect of the invention, the Helmholtz damper is designed as a retrofit component for installation in an existing burner or combustor of a gas turbine. This affords the combined damping and sealing arrangement of the Helmholtz damper according to the invention a wider range of installation possibilities. Helmholtz dampers can be easily integrated into the existing design of gas turbines and combustion systems. Vibration dampers can also be installed, for example, in such interface areas between the burner and the burner of the combustion system, in which previously conventional separate sealing and damping devices were used with corresponding separate cooling device. This form of Helmholtz damper can also be realized as a stand-alone device which can be routinely inspected and, if necessary, replaced in the gas turbine. Maintenance is thus made easier and the operating safety factor is increased.

Description of drawings

The present invention will be described in more detail below with respect to certain embodiments or examples for realizing the present invention with reference to the accompanying drawings, wherein:

1 is a schematic cross-sectional view of a first embodiment of a Helmholtz damper according to the invention and applied to a premixing burner;

Figure 2 is a schematic cross-sectional view of a second embodiment of a Helmholtz damper according to the present invention having an alternative seal form;

3 is a schematic perspective view of a third embodiment of a Helmholtz damper according to the present invention, which has a single damping space;

Fig. 4 is a schematic perspective view of a fourth embodiment of a Helmholtz damper according to the present invention, which has a segmented damping space; and

5 is a schematic cross-sectional view of a fifth embodiment of a Helmholtz damper with alternative seal positioning according to the present invention.

detailed description

A first exemplary embodiment of a Helmholtz damper 10 according to the invention, which is used in a premix burner 8 of a combustion system of a gas turbine, is shown in a schematic cross-sectional view in FIG. 1 . A Helmholtz damper 10 is mounted on the interface between the premix burner 8 and the front panel 7 of the burner of the gas turbine. In order to provide the required damping effect in terms of thermoacoustic vibrations during operation of the gas turbine, the Helmholtz damper 10 has a casing 1 which defines in a corresponding groove the side of the premixing burner 8 Rectangular shock absorber space 11 on the outside. The envelope 1 of the shock absorber 10 is also provided with a neck portion 2 in elongated form. With the elongated neck section 2 , the Helmholtz damper 10 is mounted at the interface between the premix burner 8 and the front panel 7 . For this purpose fastening means 5 in the form of a straight wall portion, such as a flange suitable for mounting onto the outer side of the premix burner 8 , are provided radially inside the neck portion 2 . A flow path F for cooling and purge air is provided, which extends from the inlet hole 6 to the outlet hole 3 through the damper space 11 and the neck portion 5 . The latter is contained in the neck portion 2 of the shock absorber 10 . In this embodiment, the outlet opening 3 is formed by the free end of the tubular neck part 2 . By virtue of this flow path F of the cooling and purge air, the Helmholtz damper 10 is cooled, thereby maintaining the required temperature for stable operation and even with varying pressure oscillations during operation of the gas turbine The required damping effect can also be achieved under certain conditions. The air flow F of cooling and purge air is particularly required for cooling the neck portion 2 of the Helmholtz damper 10 which is arranged closer to the hot gases of the combustion chamber.

According to the invention, the Helmholtz damper 10 also has a seal 4 at the neck part 2 . In this example of realization, the seal 4 is arranged radially outside the neck portion 2 and contacts the front panel 7 in order to provide the required sealing action. The position of the seal 4 at the neck portion 2 is such that the cooling and purge air from the flow path F of the outlet hole 3 passes around or along the seal 4, especially towards the inside of the combustion system (i.e. towards the combustor of the gas turbine). The front end of the seal 4 of the hot gas) passes through. The sealing of the Helmholtz damper 10 is achieved by this specific arrangement and positioning of the seal 4 of the Helmholtz damper 10 relative to the outlet opening 3 of the flow path F of the cooling and purge air An efficient and simultaneous cooling of the element 4 and of the enclosure 1 . The neck portion 2 is formed with sufficient length to arrange the seal 4 at the radially outer side of the enclosure 1 . The front end of the neck part 2 forms an outlet hole 3 for a flow path F of cooling and purge air which is supplied from a common cooling air supply for the shock absorber 10 and the seal 4 . With this arrangement and positioning of the seal 4 relative to the outlet opening 3 of the enclosure 1 , the same air flow F serves the purpose of cooling the shock absorber 10 and especially the neck portion 2 of the shock absorber 10 as well as the seal 4 . According to the invention, it is therefore not necessary to provide a separate cooling device for efficient sealing and damping of the Helmholtz damper 10 . The amount of cooling air required is thus greatly reduced, ie up to half of that required for such conventional damping and sealing arrangements in gas turbines.

Thus, the complexity of construction and design of the sealing/damping device is also reduced. By virtue of the invention, the overall costs of sealing and damping arrangements for such burner systems for gas turbines are thus also reduced. The seal 4 may be an integral part of the neck part 2 of the Helmholtz damper 10 or may be connected to the neck part 2 by any suitable connection means, such as welding, screw means or the like. The seal 4 in the realization shown in FIG. 1 is a spring-type seal, for example a so-called hula seal, for a sufficiently large displacement within a certain elastic range. Between the premix burner 8 and the front panel 7 , the seal has several leaf springs forming a semicircular ring facing radially outward of the Helmholtz damper 10 . Other types of seals 4 can also be used for the sealing effect of the Helmholtz damper 10 according to the invention. Also, alternative positions for arranging the seal 4 are feasible, as long as the position of the seal 4 is such that the air flow F of the cooling and purge air from inside the Helmholtz damper 10 passes through at least a part of the seal 4 , For example the front part of the seal in order to provide the necessary cooling for the seal as well as cooling of the envelope 1 and the neck part 2 of the shock absorber 10 . By virtue of the specific design of the Helmholtz damper 10 according to the invention, an efficient sealing and damping function is ensured in one and the same device. Operational stability of the gas turbine is also imparted since the amount of cooling air required is greatly reduced. With the relatively low amount of cooling air flow mixed with the gases in the combustor, _NOx and CO emissions are also lower compared to conventional damping and sealing arrangements for gas turbines.

A possible embodiment of the Helmholtz damper 10 with combined sealing and damping function is in particular the interface between the burner and associated components of the burner and gas turbine. For example, the shock absorber 10 according to the present invention may be applied to EV burners (peripheral swirl burners), AEV burners, BEV burners and SEV burners (sequential swirl burner )Interface. It should be noted, however, that the application possibilities of the Helmholtz damper of the invention are not limited to these types of burners or burners, but that the invention can be applied to other interfaces in gas turbines, e.g. Liner-front panel interface or liner-bracket interface for sequential combustion systems. In any of these embodiments, sealing and damping of thermoacoustic vibrations are necessary, and with the Helmholtz damper 10 of the present invention, the required cooling and Both functions are efficiently provided under the conditions of the amount of purge air.

A second implementation example is shown in the schematic cross-sectional view of FIG. 2 . Also in the case of this second implementation example, the Helmholtz damper 10 of the invention is provided with a substantially rectangular enclosure 1 forming a damping space 11 into which an air flow F of purge and cooling air is directed Through the damping space 11. Cooling air enters at the inlet hole 6 provided at the side wall of the enclosure 1, passes through the interior of the damping space 11, and flows out through the outlet hole 3, which is the neck portion of the Helmholtz damper 10 2 front holes. Cooling air from the outlet hole 3 passes through the front part of the seal 4 provided to seal the combustor chamber and prevents the temperature from rising due to the flow of hot gas H in the combustor. The neck part 2 is provided with an elongated form, so that the fastening means 3 as well as the seal 4 can be integrated into the Helmholtz shock absorber 10 at this neck part 2 . In contrast to the first embodiment described with reference to FIG. 1 , this second embodiment according to FIG. 2 has a seal 4 located radially inside the damper 10 and the associated burner system or gas turbine. Connecting means 3 are formed radially outside of the Helmholtz damper 10 in the form of a straight wall of the neck portion 2, by means of which the damper 10 is fixedly connected to the bushing 9 of the gas turbine. On the radially inner side, the neck part 2 is provided with a seal 4 , which in this realization example is an E-seal. A tight seal inside the burner chamber is provided by inserting the seal 4 between the radially inner side of the neck portion and the burner front panel 7, wherein the hot burner gases H are indicated by the arrow H in FIG. 2 Sexually shown and flowing. Also here, the cooling air flow F coming from the inlet hole 6 and passing through the neck portion 2 in order to flow out of the outlet hole 3 passes along the lateral front surface of the seal 4 so that the seal 4 is damped with Helmholtz The cooling of the device 10 itself is compared to being cooled by the same cooling air flow F.

At the outlet hole 3, flow guiding means (not shown in Fig. 2) may be provided for directing the cooling and purge air flow F from the direction of the longitudinal axis of the neck part 2, in particular towards the seal 4, in this embodiment , the seal 4 is arranged laterally on the radially inner side of the neck portion 2 . By virtue of this measure, the cooling effect is increased even further. Likewise, in this embodiment of the Helmholtz damper 10 according to the invention, the seal 4 and the housing 1 are provided with a common cooling air supply. The supply of cooling air from the inlet aperture 6 can be formed by any conventional air flow generating means, which are known to those skilled in the art. For example, the cooling air may be bypass air from the compressor of the gas turbine, or may be separate cooling air from outside the gas turbine. With this design of the Helmholtz damper 10 according to the invention, the seal is protected by the cooling air flow from the outlet opening 3 without requiring a separate cooling device for an efficient sealing action.

In this way, the Helmholtz damper 10 of the present invention is a combination of two functions, vibratory damping and cooling of the seal, performed in a very efficient and compact manner. Due to the common components and synergies achieved by this design of the Helmholtz damper 10, not only the amount of cooling and purge air required is reduced by the invention compared to conventional gas turbines, but also Total cost of seals and dampers. According to an advantageous aspect of the invention, the Helmholtz damper 10 is formed as a self-contained unit which can be easily maintained and, if required, replaced. However, the invention is not restricted to this realization, and the Helmholtz damper 10 may also be an integral part of other components of the gas turbine. Also with regard to the specific form of the enclosure 1 and the position of the seal 4 relative to the enclosure 1 , the invention is not restricted to the realization shown. For example, the neck portion 2 may be located in the middle of the enclosure 1 instead of the lateral position as shown in the embodiment of FIGS. 1 and 2 . Likewise, the positions of the inlet orifice 6 and the outlet orifice 3 may be modified within the scope of the invention.

Figures 3 and 4 further show schematic perspective views of two different implementation examples of the Helmholtz damper 10 according to the invention: It should be noted that the damper 10 is only shown schematically in Figures 3 and 4 The damper 10 is generally not a rectilinear type, but has an overall annular form in order to be mounted on the circumferential outside of the circular member of the combustor system of the gas turbine. Also here, the vibration absorber 10 has a casing 1 which forms a vibration-damping space 11 in a substantially rectilinear form or in a square cross-section. The enclosure 1 is laterally formed with a neck portion 2 in which several outlet holes 3 are provided for the air flow of cooling and purge air from the inlet holes (not shown in Figures 3 and 4). In the neck portion 2, the radially outer side (upper side in FIGS. 3 and 4 ) is formed as a flat wall portion, which serves as a fastening device 5 for firmly mounting the shock absorber 10 on the gas turbine. in the burner system. On the opposite side of the neck portion 2 there is also provided a seal 4 which in this case is a spring-type seal, for example a hula seal, as is the case with the first embodiment of FIG. 1 . In contrast to the first embodiment of FIG. 1 , in this embodiment of FIGS. 3 and 4 the seal 4 is formed radially inside the neck portion 2 . Depending on the specific flow of hot gases in the combustion system, the seal 4 on the neck portion 2 of the shock absorber 10 can be located in a radially outer or inner position as required.

According to the embodiment shown in the schematic diagram of FIG. 3 , the enclosure 1 is a single volume, which forms a single damping volume 11 . This realization is particularly suitable for damping vibrations at low frequencies. On the other hand, according to the implementation example of FIG. 4 , several internal partition walls are formed in the damper space 11 (ie, inside the enclosure 1 ), thereby creating segmented damping spaces. This embodiment of the Helmholtz damper 10 according to the invention is particularly suitable for high-frequency vibrations. Through this modification of the internal form of the enclosure 1 , the Helmholtz damper 10 can be adapted to different types of applications and operating situations of the gas turbine and burner interface. In addition to this example of a possible modification of the Helmholtz damper 10, the damper 10 can also be modified by other means, taking into account the frequency range suitable for its damping action: for example, the damper space itself can be modified , the length of the neck and the area of the exit hole and the form of the shell 1, so that the Helmholtz damper 10 is suitable for different frequencies, or it can be flexibly used for vibration damping of multiple frequencies. The Helmholtz damper 10 according to the invention is especially designed as a retrofit component which can also be installed in an existing combustion system of a gas turbine. For the purpose of installation and integration in the open space and area of the combustion system, the Helmholtz damper 10 of the present invention can also be designed as a telescopic structure.

Finally, in FIG. 5 , a fifth embodiment of a Helmholtz damper 10 according to the invention for a combustor of a gas turbine is shown in a schematic cross-sectional view. Also in this implementation example, a Helmholtz damper 10 is applied to the premix burner 8 and through the elongated straight wall in the neck portion 2 of the enclosure 1 of the Helmholtz damper 10 The fastening device 5 of the form is connected to the front panel 7 of the combustion chamber or burner. The enclosure 1 forms a damping space 11 in rectilinear cross-section, in which inlet holes 6 for cooling and purge air and outlet holes 3 are provided. Arrows F in FIG. 5 represent the air flow path for this cooling and purge air from a common supply of cooling air for cooling the shock absorber 10 as well as the seal 4 (not shown in FIG. 5 ). show). In this realization according to FIG. 5 , the seal 4 is in a radially inner position with respect to the axis of rotation of the gas turbine. Also in this implementation, the seal 4 may be a spring-type seal, such as a hula seal or an E-seal, characterized by a premixed injection combustion There is a great possibility of displacement between the burner 8 and the front panel 7 of the burner. The seal 4 is cooled by the cooling and purge air from the outlet hole 3, so that the cooling air flow F forms a protection for the seal 4 from the high temperature of the hot gases in the adjacent combustion chamber of the gas turbine. In the case of the realization according to FIG. 5 , this also means that a common cooling air flow F is used for cooling in particular the neck part 2 of the Helmholtz damper 10 as well as the seal 4 which is arranged adjacent to the neck. In the area of the outlet hole 3 of the part 2. With this realization, the required mass flow of cooling air is greatly reduced, since both elements, namely the sealing element and the damper element, are cooled by the same cooling air flow F. Both basic elements use the same device for supplying cooling air, making the shock absorber/seal less complex in terms of its construction. The overall costs are thus also limited.

The Helmholtz damper 10 according to the invention can have different forms relative to the casing 1 , for example an elongated form or a more compressed form, depending on the design of the respective gas turbine. Also, the type of seal used at the region of the neck portion of the Helmholtz damper 10 of the present invention may differ from the example shown in the above description. Also, the positions of the inlet orifice 6 and the outlet orifice 3 may be different compared to the implementation example described above. Assuming that the same cooling and purge air flow F is used for cooling the shock absorber 10 and the seal 4, the invention can be realized in a wide variety of possible designs without departing from the scope of protection of the appended claims.

Claims (14)

1. A Helmholtz damper (10) for a combustor of a gas turbine comprises a casing (1), and the casing (1) limits a damping space (11), a neck portion (2) Extends from the damping space (11) and the damping space (11) has a flow path (F) for cooling and purge air with a flow path (F) leading to the enclosure ( 1) the inlet hole (6) and the outlet hole (3), wherein the outlet hole (3) is formed in the neck part (2), characterized in that the seal (4) is in the neck part (2) is located near said outlet hole (3) for cooling and purge air so as to provide a cooling effect on said seal (4). 2. The Helmholtz shock absorber (10) according to claim 1, characterized in that there is a common cooling and purge air for the shock absorber (10) and the seal (4) supply. 3. The Helmholtz shock absorber (10) according to claim 1 or 2, characterized in that the seal (4) is an integral part of the neck part (2). 4. The Helmholtz shock absorber (10) according to any preceding claim, wherein the neck portion (2) has an extended length for accommodating the seal (4) and/or fastening means (5). 5. The Helmholtz shock absorber (10) according to any one of the preceding claims, characterized in that the outlet hole (3) is provided with a flow guide directed towards the seal (4). 6. The Helmholtz shock absorber (10) according to any one of the preceding claims, characterized in that the neck part (2) is provided with fastening means (5) for fastening to the combustion chamber interface. 7. The Helmholtz shock absorber (10) according to any one of the preceding claims, characterized in that the seal (4) is arranged relative to the casing (1) of the shock absorber (10) on the outer side of the circumference. 8. The Helmholtz shock absorber (10) according to any one of the preceding claims 1 to 6, characterized in that the seal (4) is The capsule (1) is arranged on the inner side in the circumferential direction. 9. The Helmholtz damper (10) according to any preceding claim, wherein the seal (4) is segmented along the sealing surface. 10. The Helmholtz shock absorber (10) according to any one of the preceding claims, characterized in that the seal (4) is a spring-type seal, in particular a hula seal or an E-seal . 11. The Helmholtz shock absorber (10) according to any one of the preceding claims, characterized in that the enclosure (1 ) is a single-space device. 12. The Helmholtz damper (10) according to any one of the preceding claims 1 to 10, characterized in that the enclosure (1 ) is a segmented space device. 13. The Helmholtz shock absorber (10) according to claim 12, characterized in that the enclosure (1) is designed to change the space of the shock absorber. 14. The Helmholtz damper (10) according to any one of the preceding claims, characterized in that it is designed as a retrofit part for installation in an existing burner or combustor of a gas turbine.